1. Field of the Invention This invention relates to a hydraulic chuck assembly, more particularly to a hydraulic chuck assembly which is to be provided on one end of a shaft of a CNC lathe and which is more durable and which has a stronger gripping effect than the prior art.
2. Description of the Related Art Referring to FIGS. 1, 2 and 3, the hydraulic chuck assembly (2) of a conventional CNC lathe is shown to comprise a main chuck body (21) and a plurality of grip seats (22). The bottom end of each grip seat (22) is provided with a tapered slide piece (221). The main chuck body (21) has a plurality of angularly spaced and axially extending inclined slide grooves (211) so as to movably receive the grip seats (22). The hydraulic chuck assembly (2) is provided on one end of a lathe axle means (23). A rotary actuating shaft (24) is controlled by a hydraulic fluid system (25) so as to move the main chuck body (21) axially forward or rearward, thus correspondingly moving the grip seats (22) away from or toward one another. Each of the grip seats (22) is to be provided with a grip member (not shown). The grip members can cooperatively hold a tool when the grip seats (22) are moved toward one another.
The main drawback of the above disclosed hydraulic chuck (2) is that the grip seats (22) are mounted on the main chuck body (21) at the axially extending slide grooves (211). The main chuck body (21) easily breaks at the slide grooves (211) when the tool held by the hydraulic chuck assembly (2) is relatively heavy or when the rotating speed is relatively fast. This can cause damage to the workpiece and to other parts of the lathe and can cause injury to the operator.